Does Demethylation of the Inactive X Contribute to Lupus in Women?

非活性 X 的去甲基化是否会导致女性狼疮？

• 批准号: 8597403
• 负责人: BRUCE C. RICHARDSON
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8597403
• 关键词: Affect; Animal Model; Autoantibodies; Autoimmune Diseases; Autoimmunity; B-Lymphocytes; CD4 Positive T Lymphocytes; CXCR3 gene; Cell physiology; Cells; DNA; DNA Methylation; DNA Sequence; Development; Disease; Epigenetic Process; Estrogens; Female; Flare; Frequencies; Gene Expression; Genes; Gonadal Steroid Hormones; Grant; Human; Immunoblotting; Individual; Klinefelter' s Syndrome; Link; Lupus; Methylation; MicroRNAs; Military Personnel; Modeling; Modification; Molecular; Mus; Pathogenesis; Predisposition; Prevalence; Production; Relative (related person); Reporting; Severities; Severity of illness; Signal Transduction; Systemic Lupus Erythematosus; T-Lymphocyte; TNFSF5 gene; Testing; Time; Transcript; Transfection; Turner' s Syndrome; UDP-N-acetylglucosamine-peptide beta-N-acetylglucosaminyltransferase; United States; Veterans; Woman; Work; X Chromosome; base; chemokine receptor; demethylation; design; effective therapy; environmental agent; inhibitor/antagonist; insight; lupus-like; male; men; mortality; new therapeutic target; novel; novel therapeutic intervention; novel therapeutics; overexpression; public health relevance

DESCRIPTION (provided by applicant): Systemic lupus erythematosus is a sometimes fatal autoimmune disease primarily affecting women. Estrogen contributes to disease severity, but does not completely explain the female predilection. Recent reports that men with Klinefelter's Syndrome (XXY) develop lupus at the same rate as women, while women with Turner's Syndrome (XO) are protected, suggests that having 2 X chromosomes is important for disease development. However, how a second X chromosome, which is largely inactivated, contributes to lupus in women is unclear. Evidence accumulated over more than 20 years indicates that lupus develops when genetically predisposed people are exposed to environmental agents that cause DNA demethylation in T cells, and that demethylated female T cells are sufficient to cause lupus-like autoimmunity. Work from the Richardson lab has shown that the B cell costimulatory molecule CD40L, encoded on the X chromosome and known to be overexpressed on lupus T cells, is overexpressed on T cells from women but not men with lupus because the gene on the inactive female X demethylates to cause biallelic expression, while men can only transcribe from one gene. Preliminary evidence suggests that demethylated T cells from women also overexpress other X chromosome genes including the chemokine receptor CXCR3, the signaling regulator OGT, and 6 microRNAs. Based on these observations we hypothesize that demethylation of genes on the inactive X predisposes women to lupus. We will test this hypothesis by: 1. Using high throughput DNA sequencing to compare methylation of CXCR3, OGT, the 6 miRNA genes and other X chromosome genes in CD4+ T cells from healthy men and women, with and without treatment with DNA methylation inhibitors, 2. Using high throughput DNA sequencing to compare methylation of CXCR3, OGT, the 6 miRNA genes and other X chromosome genes in CD4+ T cells from men and women with lupus matched for disease activity, 3. Determining the consequences of OGT overexpression on CD4+ T cell gene expression using transfections, microarrays and immunoblotting, and identify the miRNA target transcripts using Argonaute pulldowns followed by array analyses or sequencing, and 4. Determining if overexpressing CD40L, CXCR3, OGT or X chromosome miRNAs in a recently developed murine lupus model increases the severity of lupus in males to approximate the severity in females. We anticipate that these studies will confirm that women are predisposed to lupus in part because they can overexpress more genes than men, identify the molecules responsible, and thereby identify new therapeutic targets for women with lupus. PUBLIC HEALTH RELEVANCE: According to a recent estimate, SLE afflicts more than 130,000 individuals in the United States. Of these, nearly 90% are women, and women now comprise a significant number of military veterans. Current estimates reveal that the mortality rate of women with lupus is as high as 17.6 per million per year, indicating that current therapies are still imperfect. The design of more effective treatments will require a clear understanding of lupus pathogenesis. The studies described in this applicatiion will characterize molecular mechanisms predisposing women to lupus and thus may contribute to the design of safer and more effective therapies for this disease, and possibly for other autoimmune diseases that afflict our female veterans.

描述（由申请人提供）： 全身性红斑狼疮有时是一种致命的自身免疫性疾病，主要影响女性。雌激素有助于疾病的严重程度，但不能完全解释女性的偏爱。最近的报道称，Klinefelter综合征（XXY）的男性与女性相同，而特纳综合症（XO）的女性受到保护，这表明患有2 X染色体对疾病的发展很重要。但是，第二个X染色体在很大程度上被灭活的X染色体如何导致女性狼疮。在20多年来积累的证据表明，当遗传易感的人暴露于导致T细胞中DNA脱甲基化的环境药物时，狼疮会出现，并且脱甲基化的雌性T细胞足以引起狼疮样的自身免疫性。 Richardson Lab的工作表明，B细胞共刺激分子CD40L编码在X染色体上，已知在狼疮T细胞上过表达的B细胞对女性的T细胞过表达，但没有狼疮的男性，因为狼疮的基因demethylate demethylates上的X甲基甲酯上的基因会引起男性表达，而男性则只能从一个Gene中crantrations crantration。初步证据表明，女性的脱甲基化T细胞也过表达其他X染色体基因，包括趋化因子受体CXCR3，信号调节剂OGT和6个microRNA。基于这些观察结果，我们假设基因在非活性x上的脱甲基化使女性遭受狼疮的偏见。我们将通过：1。使用高吞吐量DNA测序来比较来自健康男性和女性的CD4+ T细胞中CXCR3，OGT，6个miRNA基因和其他X染色体基因的甲基化，并与其他DNA甲基化抑制剂相比，使用和无需处理其他甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基甲基（Chr）。狼疮男性和女性的CD4+ T细胞中的基因与疾病活性相匹配，3。使用转染，微阵列和免疫印迹确定OGT过表达对CD4+ T细胞基因表达的后果，并使用Argonaute pulldowns识别miRNA目标转录，然后使用Argonaute pulldowns，然后通过阵列分析或序列cdccr，并确定ogcress ogcress cdcr，并确定ogsress ogsress og。在最近开发的鼠狼疮模型中，染色体miRNA增加了男性狼疮的严重程度，以近似女性的严重程度。我们预计这些研究将证实女性偏爱狼疮的部分原因是它们可以比男性过表达更多的基因，确定负责的分子，从而确定狼疮女性的新治疗靶标。 公共卫生相关性： 根据最近的估计，SLE在美国遭受了13万多人的困扰。其中，妇女近90％，现在妇女组成了大量退伍军人。目前的估计表明，狼疮女性的死亡率每年高达每百万美元，这表明目前的疗法仍然不完善。更有效治疗的设计将需要清楚地了解狼疮的发病机理。在本应用中描述的研究将表征使女性诱发狼疮的分子机制，因此可能有助于设计这种疾病的更安全，更有效的疗法，并可能导致困扰我们女性退伍军人的其他自身免疫性疾病。